1. The Colts are 4-2, one game ahead of Houston atop the AFC South, and in the top half of most NFL team statistics, including No. 1 in passing offense. They are No. 16 in rushing offense. But what about the defense, ranked No. 11 against the rush and No. 14 against the pass. Do they have enough on defense to augment the explosive offense, and who are the leaders on defense in Indianapolis?

Continual questions are understandably asked about this 3-4 defense, although the Colts have been able to generate 17 sacks and come up with 12 turnovers despite a lost season for reigning sack champion Robert Mathis (Achilles) and the current four-game suspension absence of safety LaRon Landry. Defensive end Cory Redding is the vocal leader, and everybody else kind of follows him. Cornerbacks Vontae Davis and Greg Toler have been solid, which allows coordinator Greg Manusky to dial up blitzes. In terms of production, nobody is having a better season than inside linebacker D’Qwell Jackson. The offseason free-agent addition from Cleveland has a team-high 45 tackles, three sacks, one forced fumble and one fumble recovery. The defense has had its lapses, but is No. 1 in stopping opponents on third down, which gives hope that the unit could hold up its end come the playoffs in January, when it matters most.

2. Quarterback Andrew Luck is in the midst of a breakout season. To what extent has he made Colts fans forget about his predecessor, five-time NFL MVP Peyton Manning, now with the Broncos?

Some fans will never forgive owner Jim Irsay for parting with Manning. But many fans now realize that Luck is one of the NFL’s best young talents and the Colts have a promising future with No. 12 taking the snaps. Luck is taking the statistical step to show just how great he can be, he just has to cut down on risky throws and, ultimately, guide this team on a deep playoff run. Great players are remembered for many things, but even Manning was dogged for much of his career until he won Super Bowl XLI. Championships define great quarterbacks. Luck knows this, not that he’s concerned about how he’s perceived outside of the locker room. It’s about winning games and not letting his teammates down. That’s why his teammates love him. Should he take that championship step, some day, and enjoy the longevity of Manning, Luck will be mentioned in the same sentence as Peyton, which most would have thought impossible when Irsay made his seemingly unthinkable 2011 roster cut of the player that put the Indianapolis Colts on the NFL map.

3. What is wrong with running back Trent Richardson, the third overall pick of the 2012 NFL Draft, and do you think the Colts regret adding him last season via trade for a first-round draft pick after Vick Ballard went down? Richardson eventually lost his starting job to holdover Donald Brown after being demoted in Week 13 last season. They let Brown go to San Diego and kept Richardson. Will Richardson even be as good as Brown, who's averaged 4.3 yards per carry in his career compared to Richardson's paltry 3.3?

Most observers are of the opinion Richardson wasn’t worth the first-round pick traded to Cleveland to acquire him. He’s been better this season, although his numbers don’t jump off the stat sheet each week. And, to be honest, Ahmad Bradshaw has been better. But the Colts say they are convinced Richardson will continue to improve and be the player they wanted. Time will tell, but Richardson still has a lot to prove. The clock is ticking. He has one more year on his contract, and he won’t be expensive to keep around for another year, but the Colts must decide during that time if he is their future at running back. It will be interesting to see if general manager Ryan Grigson drafts a running back with a high-round pick. That would be an obvious indicator that they are looking beyond Richardson’s contract and planning for life without him, should he fail to put up the steady numbers to keep him.

4. Running back Ahmad Bradshaw looks to have plenty left in the tank as a ground-gainer with 4.7 yards per carry, and he's been a surprising asset in the Colts' passing game, especially in the red zone with those five receiving touchdowns, already a career high. The worry with Bradshaw is potential injury, which can't be predicted. He's played a full 16 games just once in his eight-year career, missing an average of three games a season his first seven years, including a career-high nine games last year in his first season with the Colts. How important is he to the offense, and how do you think the Colts would fare if they were to lose him for an extended period of time and forced to rely on the underperforming Richardson?

That’s why Richardson starts and they mix in Bradshaw, because they want to keep Bradshaw fresh and as injury free as possible. It’s not who starts, as is often said, it’s who finishes. And Bradshaw is a proven finisher. He plays so hard, with such determination, but you can’t help but worry about what would happen if he goes down again. Should that happen, the Colts would switch to a tandem with Richardson and former Bengal Daniel “Boom” Herron, who hasn’t had much playing time but delivered enough in preseason to earn a roster spot. Bottom line, the Colts typically pass to set up the run, just like in the Manning days. They’ve had some encouraging games rushing the football, but they’ve also been reminded they can’t just play smashmouth and slam it away at defenses. That typically doesn’t work.

5. Colts owner Jim Irsay recently completed his six-game suspension handed down by NFL Commissioner Roger Goodell prior to the team's season opener in Denver, preventing Irsay from having any contact on football matters with the team. Irsay pleaded guilty to a misdemeanor count of driving while under the influence (DWI) after he was arrested March 16 near his home in Carmel. Some in the media termed it a relapse to an addiction to painkillers. What does the team think of Irsay?

Irsay’s much-publicized plight hasn’t had the negative impact on players and team personnel as most might think. Perhaps it’s because he’s still the boss and writes the checks, but players continually speak well of him, carefully walking a fine line as to not condone his transgression, but saying they want to win for him. They hope he gets the care he needs to beat his longtime addiction. They know he’s been around the NFL for more than four decades and cares deeply about winning. He’s always been generous with his players, splurging on Christmas gifts and, until his suspension, being a visible locker-room presence before and after games. That won’t change because Colts coaches want the owner in there, reiterating the Colts are a family unit that stays together regardless of the outcome. Granted, the publicity was embarrassing, but this team has stayed focused. As the Colts continue to win, the headlines inevitably shift more to how they are performing instead of their owner’s issues.

Phillip B. Wilson can be found on Twitter (@pwilson24), Facebook and Google+.